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Best grease for my Meade etx 90 EC gears

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#1 LordKwad

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Posted 28 February 2020 - 04:00 PM

Apologies if this is in the wrong place.

Like the title says I need advice on what grease Ivan put in my etx 90 mount, it's for the plastic gear drives.

Basically I had a gear break so I replaced it but stupidly I cleaned off all the grease on both the Ra and Dec axis and out lithium grease on but now when I slew in any speed but max the mount judders and is no longer smooth.

Could the issue be because I've used the wrong grease??

 



#2 photoracer18

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Posted 28 February 2020 - 04:03 PM

If you live north you need a low temperature grease, south not so much. I saw a post by a guy from Anchorage who quoted exact brand name grease to use. Otherwise I usually use Lithium grease from the auto stores.



#3 LordKwad

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Posted 28 February 2020 - 04:09 PM

Its strange as the only issue my mount had was a sine broken gear now after fixing it other issues have appeared, I'm sure it must be down to the grease as that's the only thing I've changed other than a gear.

I've read alot saying lithium grease is bad for our mounts and something called super lube is best but I want other options.

I've asked Meade but I don't think there support is up to much.



#4 sg6

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Posted 28 February 2020 - 04:27 PM

Personally I would not think it is the grease.

Did you have to take the gears off to repair? Just thinking they are not quite right in regards alignment of them.



#5 GalaxyPiper

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Posted 28 February 2020 - 04:37 PM

Do not use Lithium, in low temperatures it sets up like wax...it is not the right lubrication.

And you have to be careful about lubrication's that won't melt plastic gears.

 

This may be the grease you may find useful. Walmart sells it in small tubes.

 

https://www.lubrican...astislip-grease


Edited by GalaxyPiper, 28 February 2020 - 04:44 PM.


#6 LordKwad

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Posted 28 February 2020 - 04:59 PM

Personally I would not think it is the grease.

Did you have to take the gears off to repair? Just thinking they are not quite right in regards alignment of them.

I did take the gears out of the mount to repair, its strange as they soon fine on full speed but anything else and it doesn't work as well any more. 

I've made use everything is set in properly and made sure the worm gears are snug but freely moving.

I just hope I haven't busted the much as I e had it a week and I don't need to be £140 down.



#7 GalaxyPiper

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Posted 28 February 2020 - 05:07 PM

I did take the gears out of the mount to repair, its strange as they soon fine on full speed but anything else and it doesn't work as well any more. 

I've made use everything is set in properly and made sure the worm gears are snug but freely moving.

I just hope I haven't busted the much as I e had it a week and I don't need to be £140 down.

Worm gear dives usual require an adjustment for lash against the main drive gear. You may want to look at that!

If it's too tight, it can cause problems, if it too lose, it can cause chattering.


Edited by GalaxyPiper, 28 February 2020 - 09:45 PM.


#8 LordKwad

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Posted 28 February 2020 - 05:12 PM

I hope that's an easy issue to solve as I have no idea what that means or even how to do it with this mount. :/ 



#9 GalaxyPiper

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Posted 28 February 2020 - 05:21 PM

I hope that's an easy issue to solve as I have no idea what that means or even how to do it with this mount. :/ 

Look for a small screw in one of the bearing ends of the worm gear. it may take an Allen wrench. 

See if you can find a tech or service manual for the mount, or call the company that made it for help.

 

Best of luck to you.


Edited by GalaxyPiper, 28 February 2020 - 05:22 PM.


#10 LordKwad

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Posted 28 February 2020 - 05:31 PM

The mount doesn't actually have any bearings. 

The worm gears just have a bolt and washer's.

O guess it's just a case of tighten the bolt and test, and then the opposite until it works or doesn't work.

Meade is no real help unfortunately as the mount is discontinued so I think they have forgotten how to offer support on it.



#11 GalaxyPiper

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Posted 28 February 2020 - 09:57 PM

The mount doesn't actually have any bearings. 

The worm gears just have a bolt and washer's.

O guess it's just a case of tighten the bolt and test, and then the opposite until it works or doesn't work.

Meade is no real help unfortunately as the mount is discontinued so I think they have forgotten how to offer support on it.

Yeah, Meade is having Bankruptcy issues right now.

 

Here is  PDF of the manual:

https://www.manualsl...e-Etx-90ec.html

Manuals Lib is a pretty good source for PDF manuals, just click on the Green Downed button on the top. It's free. Never download an app that redirects you to download their version of the download, it's just invasion of your computer, and not needed.

 

Here is another manual series for the 80-90-and 125 series teescopes.

https://www.meade.co...R_Manual-lo.pdf

 

Here is a you Tube Video that might give you some clues.

https://www.youtube....h?v=GQBYz-XeTS0

 

This is a very helpful site:

http://www.weasner.c...box_repair.html  <---- Should help you the most!

 

I think that Philip screw in the middle is what sets your lash.

ETX90gearInstalled.jpg<------

 

The one between the two "L" looking brackets. That would be my guess...there are three screws holding this on, so there might be a little wiggle room there.

Good luck!

Hope this helps!


Edited by GalaxyPiper, 28 February 2020 - 10:15 PM.


#12 GalaxyPiper

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Posted 28 February 2020 - 10:35 PM

This might be better grease as well.

https://www.ebay.com/itm/372918283738



#13 LordKwad

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Posted 29 February 2020 - 03:11 AM

Yeah, Meade is having Bankruptcy issues right now.

 

Here is  PDF of the manual:

https://www.manualsl...e-Etx-90ec.html

Manuals Lib is a pretty good source for PDF manuals, just click on the Green Downed button on the top. It's free. Never download an app that redirects you to download their version of the download, it's just invasion of your computer, and not needed.

 

Here is another manual series for the 80-90-and 125 series teescopes.

https://www.meade.co...R_Manual-lo.pdf

 

Here is a you Tube Video that might give you some clues.

https://www.youtube....h?v=GQBYz-XeTS0

 

This is a very helpful site:

http://www.weasner.c...box_repair.html  <---- Should help you the most!

 

I think that Philip screw in the middle is what sets your lash.

ETX90gearInstalled.jpg<------

 

The one between the two "L" looking brackets. That would be my guess...there are three screws holding this on, so there might be a little wiggle room there.

Good luck!

Hope this helps!

I've got a feeling the mount was just sold to me as not actually working.

Its funny how even if the worm gear is removed in the Dec motion the gears still okay up and even on a slow slew speed will randomly go back to full speed but only while pressing up.

Think it's ready to bin tbh as all this is beyond my knowledge and I'm way to frustrated to try and fix stuff tbh.

AHH well on to another hobby I guess.



#14 GalaxyPiper

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Posted 29 February 2020 - 04:17 AM

I've got a feeling the mount was just sold to me as not actually working.

Its funny how even if the worm gear is removed in the Dec motion the gears still okay up and even on a slow slew speed will randomly go back to full speed but only while pressing up.

Think it's ready to bin tbh as all this is beyond my knowledge and I'm way to frustrated to try and fix stuff tbh.

AHH well on to another hobby I guess.

 

It sounds like an electronic problem with the board, which means a component is fried.

Well, if you are going to bin it, post it on Cloudy Nights Classifieds with the known problem, I'm sure someone would love a challenge, and you will get some of your coin back!

 

Best of luck.


Edited by GalaxyPiper, 29 February 2020 - 04:20 AM.


#15 LordKwad

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Posted 29 February 2020 - 04:44 AM

It sounds like an electronic problem with the board, which means a component is fried.
Well, if you are going to bin it, post it on Cloudy Nights Classifieds with the known problem, I'm sure someone would love a challenge, and you will get some of your coin back!

Best of luck.



#16 LordKwad

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Posted 29 February 2020 - 04:47 AM

I can't see how it would be a fried board when there is no signs of anything being fired, also I literally only changed a plastic gear. The electronics's didn't even get touched.
It was working ok'ish before I had to change a gear admittedly it had the normal skewing errors due to poor workman ship and everything being a bit loose.
I don't think i will ever get to the bottom of the problem. Literally no one has had the same issue.
I used to build freestyle quads so I know when boards are fired and these definitely aren't. The most I've been offered is £25 which is nothing to what I paid for it.

#17 LordKwad

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Posted 29 February 2020 - 06:20 AM

O have added a video of the strange issues I am having, you can hopefully hear how erratic the drives sound. I took the OTA off to see if it made it any better which it didn't.
https://youtu.be/OiRdHbH1zfw

#18 Ulmer Spatz

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Posted 29 February 2020 - 10:56 AM

When gears and shafts transmit force, there has to be something for them to push against. With this mount, that's generally the point at which the gear or shaft assemblies are attached to the housing plastic by screws (like the three screws that hold the worm gear assembly down). Often, there a small cracks in the plastic at these points. 

 

If you tightened the attachment screws a bit too much, it's possible that you opened the cracks a little more. This would enable gears or shafts to shift around when transmitting force and throw alignments off. I would try backing the attachment screws off perhaps 1/8 of a turn (45 degrees) or so and see if that makes a difference.


Edited by Ulmer Spatz, 29 February 2020 - 12:19 PM.

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#19 Binojunky

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Posted 29 February 2020 - 11:09 AM

A small quantity of light grease is fine for basic lubrication of gears, worms and worm wheels,  lots of people overkill and make a mountain out of a molehill, as for suggestions of lithium grease setting like wax in cold weather so gears wont turn, rubbish IMHO, no problems with the lithium grease used in the wheel bearings of any car I have ever owned at tempretures of minus 35 C. or aircraft wheel bearings serviced while in the military, D.


Edited by Binojunky, 29 February 2020 - 11:11 AM.

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#20 LordKwad

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Posted 29 February 2020 - 11:31 AM

Saying that one of the screws holding do the gear assembly of the RA drive has striped the plastic so hopefully that could be the issue.
Sunday evening is when I will be inspecting things to hopefully find the answer.

#21 GalaxyPiper

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Posted 29 February 2020 - 12:09 PM

O have added a video of the strange issues I am having, you can hopefully hear how erratic the drives sound. I took the OTA off to see if it made it any better which it didn't.
https://youtu.be/OiRdHbH1zfw

I saw the video. These telescopes were never very quiet machines. The proper grease will help quiet the gear trains and the weight of the scope also will have an effect.

I did see a little lag in both operations, this could be from wear on the brass worm gears, if there are no lash adjustments.

Unfortunately, you may have to live with it, unless you hire a machinist to make you a new set of brass worm gears. A good skilled machinist can do that.

But like I said, these telescopes were never really all that quiet.

If you are going to keep it, you will have to "massage" the problems until you are satisfied.

I'm glad you made a video, this made it clearer to everyone what you were talking about.

 

Bryan


Edited by GalaxyPiper, 29 February 2020 - 01:08 PM.


#22 GalaxyPiper

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Posted 29 February 2020 - 12:22 PM

A small quantity of light grease is fine for basic lubrication of gears, worms and worm wheels,  lots of people overkill and make a mountain out of a molehill, as for suggestions of lithium grease setting like wax in cold weather so gears wont turn, rubbish IMHO, no problems with the lithium grease used in the wheel bearings of any car I have ever owned at tempretures of minus 35 C. or aircraft wheel bearings serviced while in the military, D.

Hey there fellow Air Force mechanic,

 

It didn't say they would not turn, there are different types of spray on lithium grease. I guess I was thinking of the white lithium that is popular and has a paraffin component to it.

We never used white lithium on anything on an Aircraft. Only what was recommended in the T.O.

Over the years, the T.O. changed, and told us to use a different type of grease on Aircraft wheel bearings, but to note not to mix two different types of greases as there would be a reaction.

As you probably know, everything had to be documented in the Aircraft's maintenance logs and signed off. 

 

I apologize for not making it a little clearer, as I was thinking of the 'White' lithium grease.

 

Just so you know, I worked on C-141's, KC-135's, and C-17's...


Edited by GalaxyPiper, 29 February 2020 - 12:25 PM.

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#23 LordKwad

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Posted 29 February 2020 - 12:38 PM

Yeah,I thought the video would explain it a little easier. It definitely doesn't sound as good as it did when I first had it, before I went in there messing about with stuff.
I guess I will have to try and smooth the gears, calibrate, train the drives and then sort out the backlash issue and hopefully that makes it usable again.
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#24 7howie7

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Posted 29 February 2020 - 01:27 PM

I am a bit late here, but they do make grease just for plastic gears.


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#25 LordKwad

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Posted 29 February 2020 - 01:30 PM

I am a bit late here, but they do make grease just for plastic gears.

Probably not, someone else mentioned on another site that it could of been thick grease to take away resonance and as I have replaced it with thin white lithium grease then that could cause an issue but I have no thick grease on hand to test.


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